Initial commit

Miscellaneous/calculator.cpp

@@ -0,0 +1,77 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+string s;
+
+int change(int l, int r) {
+
+	int sum = 0;
+
+	for (int i = l; i <= r; i++)
+		sum = sum * 10 + s[i] - '0';
+
+	return sum;
+}
+
+int calc(int l, int r) {
+
+	int cnt = 0, pos1 = -1, pos2 = -1, pos3 = -1;
+
+	for (int i = l; i <= r; i++) {
+
+		if (s[i] == '(')
+			cnt++;
+		if (s[i] == ')')
+			cnt--;
+
+		if (cnt <= 0 && (s[i] == '+' || s[i] == '-'))
+			pos1 = i;
+		if (cnt <= 0 && (s[i] == '*' || s[i] == '/'))
+			pos2 = i;
+		if (cnt <= 0 && s[i] == '^')
+			pos3 = i;
+	}
+
+	if (pos1 == -1 && pos2 == -1 && pos3 == -1 && cnt == 0) {
+
+		if (s[l] == '(')
+			return calc(l + 1, r - 1);
+		else
+			return change(l, r);
+	}
+
+	if (pos1 != -1) {
+
+		if (s[pos1] == '+')
+			return calc(l, pos1 - 1) + calc(pos1 + 1, r);
+		else
+			return calc(l, pos1 - 1) - calc(pos1 + 1, r);
+	}
+
+	if (pos2 != -1) {
+
+		if (s[pos2] == '*')
+			return calc(l, pos2 - 1) * calc(pos2 + 1, r);
+		else
+			return calc(l, pos2 - 1) / calc(pos2 + 1, r);
+	}
+
+	if (pos3 != -1)
+		return pow(calc(l, pos3 - 1), calc(pos3 + 1, r));
+
+	if (cnt > 0 && s[l] == '(')
+		return calc(l + 1, r);
+
+	if (cnt < 0 && s[l] == ')')
+		return calc(l, r - 1);
+	return 0;
+}
+
+int main() {
+	cin >> s;
+
+	cout << calc(0, s.length() - 1);
+
+	return 0;
+}